Hydraulic tank gauge mechanism



Feb. 14, 1939- M. w. cARRoLL HYDRAULIC TANK GAUGE MECHANISM Fi led May. 4, 1957 2 Sheets-Sheet 1 w m m Wm 4 1 3 G M W Q W a w 0 w 4 44 0 m W Q M W 6 8 &4 7 W a l M m .4 0 M 0 a N W A. a M 2 2 m ow 2 2 ATTORNEY.

Fm. M, 1-9.. M. W. ARROLL 2,147,427

H YDRAUL I C TANK GAUGE MECHAN I SM Filed May 4, 1937 2 Sheets-Sheet 2 INVENTOR.

Carr/1 Patented Feb. 14, 1939 UNlTED STATES PATENT OFFICE HYDRAULIU TANK GAUGE MECHANISM 1 Claim.

This invention relates to a tank gauge mechanism.

The invention relates more particularly to a hydraulic tank gauge especially adapted for use on fuel tanks of motor vehicles, aeroplanes and the like although the gauge is adaptable for general use.

An object of the invention is to provide means for operating the gauge, said means including a float in the fuel tank and a pressure conduit connected into the coil of the gauge proper, the gauge coil and the conduit being filled with an operating fluid preferably a light oil and means whereby the buoyancy of the float will be rendered operative to create a pressure on the operating fluid whereby the gauge proper will be actuated in accordance with the quantity of fuel in the fuel tank.

It is another object of the invention to provide means whereby the float may be maintained inactive but may be released for operation in accordance with the will of the operator.

It is a further object of the invention to provide means for regulating the capacity .of the pressure conduit containing the operating fluid in accordance with the variations in the volume of said operating fluid due to variation in the temperature thereof.

With the above and other objects in View the invention has particular relation to certain novel features of construction, operation and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings, wherein:

Figure 1 shows a side view of the complete apparatus as mounted on a motor vehicle.

Figure 2 shows a cross-sectional View of the fuel tank showing the operating mechanism mounted therein partly in section.

Figure 3 shows an enlarged fragmentary side elevation, shown partly in section.

Figure 4 shows a vertical, sectional view taken on the line 4-4 of Figure 3.

Figure 5 shows an elevational view of the gauge dial.

Figure 6 shows a plan view of the float, and

Figure 7 shows a plan view of the float controlling lever employed.

Referring now more particularly to the drawings wherein like numerals of reference designate similar parts in each of the figures, the numeral l designates the fuel containing tank which is of any conventional construction and the numeral 2 designates the gauge proper having the dial 3. The gauge 2 may be located at any convenient place. As shown, it is mounted on the instrument board 4 of the vehicle. An operating fluid line 5 is connected, at one end, into the top of the coil of the gauge 2 as shown in Figures 1 and 3.

On the tank I there is a hood 6 whose upper end may be closed by a removable cap I for ready access thereto. In assembly this hood is preferably fitted upwardly through a hole in the top of the tank and the lower end of the hood has a flange 8 which surrounds said opening and. between said flange and the top of the tank there is a gasket 9 forming a fluid tight joint. The bottom of the tank has a relatively large opening I!) therein for ready access into the tank to permit the insertion and installation of the op.- erating mechanism therein shown in Figure 2. Surrounding this opening there is a depending annular flange l I and the lower end of the opening is enlarged forming an inside annular downwardly facing shoulder against which the annular plate It abuts. Spaced guide rods l4, l4 are located in the tank with their upper ends fitted'through the flange B and the gasket ,9 as well as through the top of the tank and said upper ends are outwardly threaded to receive the securing nuts l5, IS. The lower ends of these guide rods are fitted through openings in the plate 13 and are outwardly threaded to receive the nuts [6, I6 whereby said rods may be secured firmly in place and the plate l3 may be held clamped against the shoulder 12. The opening I0 is securely closed by a bottom plate I! which is fastened to the lower margin of the depending flange H.

The guide rods M are provided with the stops I8, I18 at a suitable elevation and mounted on these stops is the annular flange l9 which supports a cylinder 2!]. The upper end of this cylinder fits closely up into the hood 6 and said hood is provided with an internal, downwardly facing shoulder 2! arranged opposite the upper end of the cylinder with ,a suitable annular packing :22 interposed between the shoulder 21 and the op,- posing end of the cylinder forming a fluid tight joint. The lower end of the cylinder is countersunk into the supporting flange l9 whereby the cylinder is secured firmly in place.

The other end of the conduit 5 is connected into the hood 6, said hood forming in effect an extension of the cylinder.

There is a float 23 of any selected design and of a shape to fit into the opening Ill and to rest on the plate l3 when in inaction position. It has the spaced side openings 24, 24 which receive the guide rods l4, l4 loosely.

In the cylinder there is a plunger formed with the upwardly and downwardly opening cups 25 and 26, respectively, which fit closely against the cylinder walls. The upper end of the plunger rod 21 is attached to the plunger and the lower end of said rod is reduced, as shown in Figure 2 and fitted through a central opening 28 through the float.

On the reduced lower end of the rod 21, above and beneath the float, are the washers 29, 30 and threaded onto the lower end of the stem 21 beneath the lower washer is the nut 3|. Above the upper washer the stem is formed with an external, downwardly facing shoulder 32 against which the upper washer 29 engages to move the stem and plunger upwardly as the float moves upwardly. The openings 24 and 28 are somewhat larger than the guide rods I 4 and the reduced portion of the stem, respectively, to prevent binding and to permit free movement of the float.

There are the spaced levers 33, 33 which are suitably anchored together and which are pivoted at their outer ends to a lug 34 on the inside of the tank I. Their other ends are outwardly curved as at 3411. and embrace the retaining ring 35. This ring has the oppositely disposed studs 36, 36 which work through oblong slots 31 of the levers 33. The ring also has bearings 38, 38 which receive the guide rods l4 loosely.

A coiled pull spring 39 is connected at one end to a depending lug 40 in the top of the tank and at its other end to an upstanding lug 4| carried by the levers 33.

A cable 42 is attached at one end to the levers 33 and passes around a sheave 43 mounted in the bottom of the tank and the other end of the cable is attached to the lower end of a slidably mounted rod 44 which works closely through a sleeve-like bearing 45 extended through and secured to the tank Wall.

An operating cable 46 is connected at one end to the outer end of the rod 44. The other end of this cable is connected to an operating lever 41 of the vehicle. This cable operates over suitable sheaves 48, 49 and has a yieldable section 50 incorporated therein to relieve the cable from excess tension.

When the operating lever 41 is inactive the cable 46 will be under tension and will maintain the levers 33 and the retaining ring 35 in their lowermost position with the ring against the float to hold the float stationary. The tank I, of course, will normally contain a quantity of liquid fuel. As stated the gauge coil of easing 2, the conduit 5 and the cylinder 20 will be filled with an operating fluid preferably a light lubric'ating oil which will lubricate the parts. When this operating fluid is at normal temperature the hand 5| of the gauge will stand at zero as shown in Figure 5. If the temperature of this operating fluid is appreciably raised the operating fluid will expand causing a corresponding actuation of the hand 5|. It is necessary that provision be made for relieving the conduit 5 of the excess volume of the operating fluid due to the expansion from heat before attempting to guage the amount of the liquid in the tank I. For this purpose a cylinder 52 has been provided which is connected at one end into the conduit 5. The other end of this cylinder is equipped ,with a stufiiing box 53 through which a plunger 54 operates. This plunger is preferably polygonal in cross-sectional contour and the interior of the cylinder 52 is similarly shaped to prevent the turning of the plunger 54. An actuating rod 55 has a swiveling connection with the instrument board 4 and has a threaded connection with the plunger 54. The outer end of the rod 55 has a grip member 56 thereon accessible to the operator. If from heat the expansion of the operating fluid is suflicient to move the hand 5| from zero, when it is desired to test the quantity of liquid in the tank I, the plunger 54 should be adjusted until the hand. 5| stands at zero. The operating lever 41 may then be actuated to release the tension from the cable 46 whereupon the spring 39 will lift the retaining ring 35 from the float and permit the float to rise thus subjecting the operating fluid in the cylinder 20 to pressure from the plunger and this pressure will be transmitted to the gauge and will be indicated by the hand 5 I. The range of movement of the float will be regulated by the quantity of liquid in the tank I so that by an inspection of the gauge, under the conditions stated, the quantity of motive fluid in the tank can be at any time readily ascertained.

The conduit 5 is connected into the top of the coil of the gauge 2 to the end that said coil will at all times remain filled with the operating fluid.

The opening I0 is of sufficient size to readily admit the operating parts to be installed in said tank and to permit the Work of installation.

The drawings and description disclose what is now considered to be a preferred form of the invention by way of illustration only, while the broad principle of the invention will be defined by the appended claim.

What I claim is:

In combination, a liquid containing tank having vertical guides, a gauge adapted to be actuated by an operating fluid, a cylinder depending into the tank, a conduit leading from the upper end of the cylinder and connected to the gauge, a cylinder connected with the conduit and having a relief chamber, a piston in the tank cylinder, a float in the tank mounted to move on said guides and connected to said piston for varying the pressure of the operating fluid, a manually operable plunger for varying the capacity of the relief chamber in accordance with variations in the volume of the operating fluid, retaining means on the guides for normally maintaining the float against movement and means for releasing the 00 retaining means to permit movement of the float.

MONROE W. CARROLL. 

